Optimization of ultrasound-assisted extraction of sheep abomasum protein concentrates by response surface methodology and evaluation of their properties

Abstract The aim of this study was to extract sheep abomasum protein concentrates (SAPC) by ultrasound-assisted extraction (UAE) and to investigate the properties of SAPC. Response surface methodology and Box-Behnken design were applied to determine the optimal parameters for UAE. The maximum water-soluble protein concentration was 320.5 mg protein/g dry raw material under the optimal conditions with ultrasonic treatment time of 28 min, ultrasonic power of 450 W, liquid/solid ratio of 25 mL/g, and pH of 10. Compare with conventional extraction method (CEM), the UAE not only provided the higher protein concentration and yield but also required much shorter extraction times. Additionally, the SAPC obtained by UAE demonstrated better solubility, emulsifying properties, foaming properties and oil holding capacity as compared to CEM. However, use of the UAE method did not significantly increase the water holding capacity of SAPC.